Transient forebrain ischemia modulates focal adhesion kinase (FAK)‐mediated signal transduction in gerbil hippocampus

Abstract

Focal adhesion kinase (FAK) is thought to play a major role in conveying survival signals from extracellular matrix (ECM). Phosphorylated FAK may interact with other nonreceptor kinases such as Src, and adaptor molecule Cas, perhaps providing a pathway by which ECM may regulate cell viability. In the present study the expression and tyrosine phosphorylation of FAK, Src and Cas after 5 min of global ischemia were investigated. The primary activation/phosphorylation of FAK, observed during first 6 h after ischemic injury, was followed by its profound down‐regulation. At 72 h of reperfusion the level of phosphorylated FAK decrease to about 50% of the control. The decrease of FAK phosphorylation coincides with its proteolytic degradation. Cleavage of FAK coincided temporally with the loss of Src and Cas. Ischemia‐induced proteolytic processing of the investigated proteins may lead to the interruption of ECM‐derived signals and compromise neuronal survival.Acknowledgements: Sponsored by SCSR 4P05A 08619 and Med. Res. Ctr.